545 resultados para post-dynamic recrystallization
Resumo:
The ability to test large arrays of cell and biomaterial combinations in 3D environments is still rather limited in the context of tissue engineering and regenerative medicine. This limitation can be generally addressed by employing highly automated and reproducible methodologies. This study reports on the development of a highly versatile and upscalable method based on additive manufacturing for the fabrication of arrays of scaffolds, which are enclosed into individualized perfusion chambers. Devices containing eight scaffolds and their corresponding bioreactor chambers are simultaneously fabricated utilizing a dual extrusion additive manufacturing system. To demonstrate the versatility of the concept, the scaffolds, while enclosed into the device, are subsequently surface-coated with a biomimetic calcium phosphate layer by perfusion with simulated body fluid solution. 96 scaffolds are simultaneously seeded and cultured with human osteoblasts under highly controlled bidirectional perfusion dynamic conditions over 4 weeks. Both coated and noncoated resulting scaffolds show homogeneous cell distribution and high cell viability throughout the 4 weeks culture period and CaP-coated scaffolds result in a significantly increased cell number. The methodology developed in this work exemplifies the applicability of additive manufacturing as a tool for further automation of studies in the field of tissue engineering and regenerative medicine.
Resumo:
Richard Lewontin proposed that the ability of a scientific field to create a narrative for public understanding garners it social relevance. This article applies Lewontin's conceptual framework of the functions of science (manipulatory and explanatory) to compare and explain the current differences in perceived societal relevance of genetics/genomics and proteomics. We provide three examples to illustrate the social relevance and strong cultural narrative of genetics/genomics for which no counterpart exists for proteomics. We argue that the major difference between genetics/genomics and proteomics is that genomics has a strong explanatory function, due to the strong cultural narrative of heredity. Based on qualitative interviews and observations of proteomics conferences, we suggest that the nature of proteins, lack of public understanding, and theoretical complexity exacerbates this difference for proteomics. Lewontin's framework suggests that social scientists may find that omics sciences affect social relations in different ways than past analyses of genetics.
Resumo:
This article examines the merger between AOL and the Huffington Post. The broader issues around the merger will be investigated, especially the implication for rights, in particular free expression, and their conditions for exercise and actual exercise online. One major issue is that of the status of user-generated content and how the existing legal regime reflects the ethical concerns of users over how their content, data and information is used and commodified by the for-profit Internet intermediaries and platforms, especially when they start to merge and form concentrations. The extent to which the current legal regimes, especially human rights, deal with these problems in an adequate fashion will be assessed, along with the presentation of some suggestions of alternative approaches which may be more effective in practice.
Resumo:
There are 23,500 level crossings in Australia. In these types of environments it is important to understand what human factor issues are present and how road users and pedestrians engage with crossings. A series of on-site observations were performed over a 2-day period at a 3-track active crossing. This was followed by 52 interviews with local business owners and members of the public. Data were captured using a manual-coding scheme for recording and categorising violations. Over 700 separate road user and pedestrian violations were recorded, with representations in multiple categories. Time stamping revealed that the crossing was active for 59% of the time in some morning periods. Further, trains could take up to 4-min to arrive following its first activation. Many pedestrians jaywalked under side rails and around active boom gates. In numerous cases pedestrians put themselves at risk in order to beat or catch the approaching train, ignored signs to stop walking when the lights were flashing. Analysis of interview data identified themes associated with congestion, safety, and violations. This work offers insight into context specific issues associated with active level crossing protection.
Resumo:
The business value of information technology (IT) is realized through the continuous use of IT subsequent to users’ adoption. Understanding post-adoptive IT usage is useful in realizing potential IT business value. Most previous research on post-adoptive IT usage, however, dismisses the unintentional and unconscious aspects of usage behavior. This paper advances understanding of the unintentional, unconscious, and thereby automatic usage of IT features during the post-adoptive stage. Drawing from Social Psychology literature, we argue human behaviors can be triggered by environmental cues and directed by the person’s mental goals, thereby operating without a person’s consciousness and intentional will. On this basis, we theorize the role of a user’s innovativeness goal, as the desired state of an act to innovate, in directing the user’s unintentional, unconscious, and automatic post-adoptive IT feature usage behavior. To test the hypothesized mechanisms, a human experiment employing a priming technique, is described.